Vehicles are often used by security forces, police and the like during surveillance operations. In the simplest form, a vehicle such as a van can be parked at a convenient location and operatives can be housed in the van and view a scene through one-way windows or concealed viewing devices such as a periscope. Simple arrangements such as this are not sufficient, however, with an experienced criminal who will readily spot an unusual vehicle.
As a result remotely controlled camera devices can be used with an empty vehicle like a car. This requires concealment of the camera, recorder and transmission equipment. Again experienced criminals will note anything unusual in a vacant vehicle such as a cushion or paper handkerchief dispenser on the back window sill masking this sort of equipment. Therefore it has been usual to mount such equipment in the boot of a car with a periscope hidden in and masked by a radio aerial. A problem with this arrangement however is that the body of a car and vehicles parked close by will restrict the possible field of view from the aerial to sideways directions and the full 360.degree. will not be available.
Many known surveillance devices such as, for example, that shown in European Patent Application No. 152 181 required that the camera rotate with the periscope making it difficult to rotate the field of view through a complete 360.degree. and to continue to rotate past 360.degree. if required. Also the devices shown in that Application are bulky and would be obvious to a suspect if mounted on the roof of a vehicle.
The invention has therefore been made with these points in mind.